Apparatus for controlling a fuel injection pump, particularly for motor vehicles



Feb. 9, 1960 H. R. GROZINGER ETAL 2,924,208 APPARATUS FOR CONTROLLING AFUEL INJECTION PUMP, PARTICULARLY FOR MOTOR VEHICLES Filed Oct. 1. 1958F 7 run INJECTION PUMP /2 FUEL CONTROL R00 64% HTTORNE 5 United StatesPatent APPARATUS FOR CONTROLLING A FUEL IN- JECTION PUMP, PARTICULARLYFOR MOTOR VEHICLES Hans R. Griizinger and Herbert Gauss,Stuttgart-Unterturkheim, Germany, assignors to Daimler-BenzAlttiengesellschaft, Stuttgart-Unterturkheim, Germany ApplicationOctober 1, 1958, Serial No. 764,661

' Claims priority, application Germany October 4, 1957 11 Claims. (Cl.123-140) Our invention relates to an apparatus for controlling a fuelinjection. pump of an internal combustion engine, particularly for motorvehicles. More especially my 'invention is applicable to pumps forinjecting gasoline in motor vehicle engines in which the air-fuelmixture is compressed prior to ignition thereof.

It is the object of our invention to so control the pump that thequantity of fuel injected will be more increased upon a quick depressionof the accelerator pedal than upon a slow depression thereof, as isdesirable for a powerful acceleration of the motor vehicle.

It is a more specific object of our invention to provide improved meansfor an accurate control of the boosting of the injected quantity of fueleffected in response to a quick depression of the accelerator pedal and,more specifically, for a very exact control of the duration of suchboosting effect.

Further objects of our invention will appear from a detailed descriptionof various preferred embodiments thereof described hereinafter withreference to the accompanying drawings. We wish it to be clearlyunderstood, however, that the terms and phrases used in such detaileddescription have been chosen for the purpose of illustration rather thanthat of limitation or restriction of the invention and that theinvention is in no way limited to the details of such embodiments but iscapable of numerous modifications within the scope of the ap pendedclaims.

In the drawings: 7

Fig. 1 is a more or less diagrammatic perspective view of the fuelinjection pump equipped with our novel controlling apparatus, part ofthe intake manifold and of a vacuum-responsive device communicatingtherewith being shown in section,'and

Fig. 2 is a sectional view of a modified means responsive to the speedof the depression of the accelerator pedal shown in Fig. 1.

The fuel injection pump 10 diagrammatically illustrated in Fig. 1 has adriving shaft (not shown) geared to the crank shaft of an internalcombustion engine of a motor vehicle and injects intermittentlyaccurately metered quantities of gasoline into the intake manifold orinto the cylinders of the engine for subsequent compression of theair-fuel mixture so formed prior to igni-' tion. In order to maintain aratio of admixture of the fuel to the air favorable to ignition andcombustion the quantity of fuel injected is controlled in dependence onthe quantity of air sucked into the cylinders of the engine. For thatpurpose the pump is provided with an adjustable pump control member 12connected with a vacuum-responsive device 16 which through a suitableduct 18 permanently communicates with a port 20 of the intake manifold22, such port being located downstream of a butterfly valve 24 which byits position determines the quantity of air sucked into the cylindersand, consequently, the power output of the engine and, for this reason,is mounted in a position upstream of the port 20 enabling it toselectively more or less close or open the pump housing, schematicallyillustrated in Figure 1,

and extending outwardly therefrom. A spring 26 which is mounted over theoutwardly extending end of the slidable rod 12 and which is insertedbetween the housing and a spring supporting disk 29 fixed to the rod 12tends to hold the latter in the position in which the quantity of thefuel injected is reduced to zero. The rod 12 which is the fuel adjustingrod of the fuel pump of any conventional construction, for example,including a racktype adjusting rod is operatively connected with thevacuum-responsive device 16 and, more particularly, with a diaphragm 14thereof by a suitable chain of motion-transmitting means to be describedlater. The fuel control or adjusting rod 12 is operative in anyconventional known manner to adjust the amount of the injected fuelquantity by displacement of the rod 12 in the axial direction thereof,as is conventional and well known with fuel injection pumps.

The device 16 comprises a cup-shaped sheet metal member mounted instationary position on the housing of pump 10 and closed by the flexiblediaphragm 14. A spring 27 inserted between the diaphragm 14 and thebottom of the cup-shaped sheet metal member tends to urge the diaphragmto the left with reference to Fig. 1. The atmospheric pressure acting onthe outer face of the diaphragm 14, however, will compress the spring 27when a vacuum prevails in the intake manifold 22 downstream of thethrottle valve 24 and is communicated through the duct 18 to theinterior of the cup-shaped member. Hence, the diaphragm 14 represents anelement which is responsive to the position of the throttle valve 24 andof a suitable adjustable member mounted for actuation by the operator,such as an accelerator reduce the vacuum prevailing in the device 16,thereby.

permitting spring 27 to move diaphragm 14 outwardly. The chain ofmotion-transmitting means now to be described transfer this motion torod 12, whereby this rod will be depressed contrary to the tendencyofspring 1 26, thereby increasing the quantity of fuel injected.

The chain ofmotion-transmitting means comprises lever arms 42 and 44 andan interconnecting pin 46. The lever arm 42 has its lower end fulcrumedon a horizontal pivot 45 and its other end pivotally connected to a rod48 connected to the center of the diaphragm 14 and extendingsubstantially parallel to the rod 12. The horizontal pivot extends atright angles to the rods 12 and 48 spaced therefrom. In order to insurea rigid guidance of lever arm 42, the lower end 50 there of maybeU-shaped and provided with two coaxially disposed spaced bearingportions journaled' on the pivot 45. The lever arm 44 extendssubstantially parallel to lever arm '42 and has its upper end pivotallyconnected to the end of'rod 12, whereas its lower end is bifurcatedstraddling a horizontal rod'52 which extends substantialindicated at 54.A' spring 56 extended between a clip 58 fixed to rod 52 and an anchoringmember 60 fixed to the housing 10 tends to hold the end of rod 52 in emgagement with an abutment 62 fixed to housing 10. The

- Patented Feb. 9,1960

horizontal pin 46 which extends parallel to pin 45 and at right anglesto the rods 12, 48 and 52 is rigidly secured to the link 42 between theends thereof and extends through a vertical slot 64 formed by aloop-shaped portion 66 of link 44. 2 r

A solenoid 68 mounted on the pump housing in co-axial relationshipwiththerod '52 has a movable armature 70 rigidly connected to rod 52'and normally held by. the spring 56in the position shown. When the coil72 of solenoid 68 is energized, the armature 70-and therod 52connectedth'erewith are pulled to the right with reference to Fig. linto contact with an abutment formed-by the end of an adjustable screw74 engaging a threaded'bore of a bracket 76 fixed to the pump hous ing10-and arrested in adjustable position by a nut 78. Thebifurcated lowerend of link 44 carries a pivot pin (not shown) which extends through atransverse bore of rod 52, thereby'pivotally connecting same with thelower end of link 44. p

'The solenoid 68 and rod 52 constitute an electrc magnetic actuatorconnected with electrical impulse-producing means which areresponsive-to the speed of actuation of the adjustable member 28 in thedirectionof the arrow 80. This is the direction of actuation whichincreases the quantity of the fuel injected; When the speed of actuationof the adjustable member 28 in the direction of arrow=80 exceeds acertain limit, the impulseproducing means now to be described produce anelectrical impulse of a predetermined duration for ener-' gization ofthe electrical actuator 68. For this purpose the impulseproducing meanscomprises-a pair of relays 82 and 83, a switch 84 for-controlling therelays 82 and 83 and themeans 34 which are responsive to the speed ofactuation of the adjustable member 28 in the direction of the arrow 80.The relay 82 is a slow-acting relay, whereas'relay 83 is of'afast-acting type.

-A suitable source of current86 hasone of its terminalsgrounded, whereasthe other terminal is connected by leads 88 and 90 to one terminal ofthe coil of relay 83 and to one terminal of a switch 92 which isnormally open and'is closed upon energization of coil 83. The otherterminal of coil 83 is connected by lead 94 to one of the contactsofswitch 84, whereas the other contact thereof is grounded at 96. v

The relay coil 82 has one of its terminals grounded'at 98, whereas itsotherterminal is connected by a lead 100 to the switch 92 and by a lead102 to one terminal of a relay switch 104which is normally closed and isopenedupon energization of coil 82. The other terminal ofswitch 104 isconnected by a lead 106 to one terminal of the coil 72 of theelectromagnetic actuator, whereas the otherterminal 108 thereof isgrounded. A condenser 110 which preferably is of an adjustable type isshunted across the coil 72 being connected between theterminal 108 andthe lead 106.

"The contacts of switch84 are mounted on the/opposed ends of a pair ofparallel two armed levers "1121 and 114 fulcrumed on a common horizontalaxis 116, the other arms of these levers being connected by a tensionspring 118 which inrelaxedcondition keeps the leversin the relativeposition shown in which the switch 84 is open. The operation of ourcontrol apparatus is as follows:

In the position shown the accelerator 'pedal 28 is slightly depressedand by means of the linkage '30, 32, 34, 36 and 38 keeps the butterflythrottle valve 24' in slightly opened position. As theengine is running,its

cylinders suck air through the intake manifold 22 past theslightlyopened throttle valve 24 maintaining a substantial vacuum downstreamthereof. As this vacuum is transferred through the duct 18 to the device16,-the diaphragm 14 is pulled inwardly compressing the spring 27 r andholding the motion-transmitting linkage 42,' 44 and 46 in thepositionshown in which the pump control member 12 adjusts the pump so asto inject comdepresses the accelerator pedal 28 at a slow speed,downward motion of link 32 will be transmitted by spring 118 to the link36. As the spring 118 is more powerful than the spring 40, levers 112and 114 will swing through equal angles about their pivot 116, thuskeeping contacts of switch 84 in separated relationship. Links32 and 36moving downward in unison will rock the arm 38 so as to open thethrottle valve 24. As a result, the vacuum prevailing in the intakemanifold 22 downstream of the throttle valve will be reduced or, inother words, the pressure prevailing at; the port 20 and in the device16 will rise permitting spring 27 to push rod 48 to the left causinglever arm 42 to swing anti-clockwise and by its pin 46 to impartasimilar anti-clockwise movement to lever arm 44, whereby control member12 will be pressed inwardly contrary to the tendency of spring 26,

thereby increasing the quantities of fuel injected. The.

velocity than. lever 114, whereby the contacts of switch 84 will engageclosing a circuit through the coil of relay 83. This will immediatelyestablish a circuit extending from the ground through battery '86, lead88, lead 90, relay switch 92which is now closed, lead 100,lead 102,:relay switch 104 which is still closed, lead 106, coil 72,.

terminal 108 and ground. In this circuit the electromagnetic actuator 68will be energized, whereby armature 70 thereof will be abruptly movedinto contact with the abutment formed by screw 74. This will impart ananti-clockwise swinging movement to link 44 which is superimposed on theswinging movement imparted by the diaphragm 14, rod 48, lever arm 42 andpin'46, as above described. As a result, thejquantity of fuel injectedwill be so increased as to change the ratio of. the fuel-air mixture ina manner increasing the power output of the engine for quickacceleration of the vehicle.

"A branch of the circuit just described extends from lead through thecoil of relay 82 to the terminal 98, whereby the slow-acting relay 82will be energized simultaneously with the solenoid68. After a predeterwmined period ,of time the slow-acting relay 82 will open its normallyclosed contact 104, whereby the electrO:

magnetic actuator" will be de-energized permitting spring H 56 to returnthe rod 52 tothe position shown, thereby restoring the quantity of fuelinjected to the normal rate. From the above it will appear that thequantity of fuel injected will be more increased upon a quick depressionof the accelerator pedal 28 than upon a slow depression thereof. r

The device 34 which is responsive to the speed of actuation of theadjustable member 28 in a direction increasing the quantity of fuelinjected is capable of nu.- merous modifications. In Fig.2 .we haveshown such a modification. In thisv embodiment the links 32 and 36 r arepivoted by a pivot pin 120 to each other and to an arm 122 of acylindrical housing 124 mountedfor rotation about its axis 126 whichextends at right angles to the links 32, .36 at a suitable distancetherefrom. Within the housing 124 a member 128is mounted on the pivot126 for rotation. A tension spring 130 having one of its ends anchoredto the housing 124 and the other end attached to the member 128 tends'toturn the same into anti-clockwise direction with reference to the houswing'124, thereby keeping a radial face 132. of the member-128'incontactwith'a stop pin 134 which is fixed r to the housing 124pandextends into the latter in radial direction. The radial face 132 ofthemember 128 is:

formed by a recess into which a contact arm 136 extends through anaperture 138 of the housing from a bracket 140 of insulating materialfixed to the outside of the housing 124. The lead 94 is connected to thecontact arm 136, whereas the housing 124 is grounded. A radial face 142of the member 128 is slightly spaced from the contact arm 136 when theparts assume the position shown in Fig. 2. They will remain in thisrelative position upon a slow depression of the accelerator pedal 28,Fig. 1, causing rotation of the housing 30 and the elements mountedthereon at a low angular speed. When the driver desirous of acceleratingthe vehicle depresses the pedal 28 abruptly, however, the heavy massconstituted by the member 128 will not be able to follow the rotation ofthe housing 124 but will lag behind, thereby stretching spring 130and-causing contact between contact arm 136 and the face 142, wherebyrelay 83 will be energized.

If desired, the restoration of the rotary member 128 to its normalposition relative to the housing 124 may be retarded by suitable means,such as hydraulic dampening means.

In the embodiment shown, the rotary member 128 is provided with a secondrecess for this purpose and a radial partition 142 suitably fixed to thehousing 124 extends into this recess dividing same into a pair ofchambers 144 and 146 which are filled with a suitable liquid. Theclearance between the rotary member 128 and the inner surface of thehousing 124 is preferably so small that the liquid in the chambers 144and 146 cannot escape therethrough. The partition 142 has an aperturewhich is normally closed by a spherical valve member 148 resilientlyheld in closed position by a leaf spring 1500. The spherical valvemember 148 constitutes a check valve opening into chamber 146. Rotationof member 128 in clockwise direction relative to housing 124 in responseto an abrupt depression of the accelerator pedal 28 causes liquid to bedisplaced from chamber 144 into chamber 146 past the check valve 148which will not substantially obstruct such flow. The relative restoringrotation of member 128 in anticlockwise direction, however, is sloweddown by the liquid entrapped in chamber 146 which must seep past thepartition 142 into chamber 144. This will insure maintenance of theenergization of relay 83 for a period of time suflicient to insure areliable response of such relay.

The responsiveness of the device illustrated in Fig. 2 to abruptdepression of the accelerator pedal may be increased by insuring thatthe rotary velocity of the housing 124 will be high relative to thespeed of displacement of the links 32, 36. This may be insured byreducing the length of arm 122 to a minimum or by other suitable means.

The duration of energization of the electromagnetic actuator may beincreased, if desired, by increasing the capacity of the condenser 110.

While the invention has been described in connection with a number ofpreferred embodiments thereof, it will be understood that it is capableof further modification, and this application is intended to cover anyvariations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures fromthe present disclosure as come within known or customary practice in theart to which the invention pertains, and as fall within the scope of theinvention or the limits of the appended claims.

What we claim is:

1. Apparatus for controlling a fuel injection pump of an internalcombustion engine comprising an adjustable pump control member formetering the quantity of fuel injected by the pump, an adjustable membermounted for actuation by the operator, an element responsive to theposition of said adjustable member, a chain of motiontransmitting meansconnecting said element with said '6 control member and enabling saidelement to determine said quantity of fuel in dependence on saidposition, an electromagnetic actuator connected with said means forincreasing, when energized, said quantity of fuel determined by saidelement, a switch for energizing said electromagnetic actuator, andmeans co-ordinated to said switch and responsive to the speed ofactuation of said adjustable member in a direction increasing saidquantity for actuating said switch to cause energization of saidactuator, when said speed exceeds a certain limit, where by saidquantity will be more increased upon a quick actuation of saidadjustable member by the operator than upon a slow actuation thereof.

2. Apparatus as claimed in claim 1 further comprising means forde-energizing said actuator after it has been energized for apredetermined period of time.

3. Apparatus for controlling a fuel injection pump of an internalcombustion engine comprising an adjustable pump control member formetering the quantity of fuel injected by the pump, an adjustablemembermounted for actuation by the operator, an element responsive tothe position of said adjustable member, a chain of motion-transmittingmeans connecting said element with said control member and enabling saidelement to determine said quantity of fuel in dependence on saidposition, an electromagnetic atcuator connected with said means forincreasing, when energized, said quantity of fuel determined by saidadjustable member, impulse-producing means responsive to the speed ofactuation of said adjustable member in a direction increasing saidquantity for producing an electrical impulse when said speed exceeds acertain limit, and means connecting said impulse-producing means withsaid electromagnetic actuator for energization thereof by said impulse,whereby said quantity will be more increased upon a quick actuation ofsaid adjustable member by the operator than upon a slow actuationthereof.

4. Apparatus as claimed in claim 3 in which said impulse-producing meanscomprises a pair of relays, a switch for controlling said relays, meansresponsive to the speed of actuation of said adjustable member in adirection increasing said quantity for actuating said swltch to causeenergization of said relays, one of said relays being a fast-actingrelay including a switch causing energization of said electromagneticactuator and the other relay being a relatively slow-acting relaycausing de-energization of said electro-magnetic actuator.

5. Apparatus as claimed in claim 4 in which the switch included in saidfast-acting relay is mounted to be closed upon energization thereof andthe switch included in that relatively slow-acting relay is mounted tobe opened by energization thereof, both switches, a source of currentand said electromagnetic actuator being included in a common circuit.

6. Apparatus as claimed in claim 3, further comprising an electricalcondenser shunted across the winding of said electromagnetic actuator.

7. Apparatus as claimed in claim 1 in which said electro-magneticactuator includes a movable armature connected with saidmotion-transmitting means, said apparatus further comprising anadjustable stop so mounted as to limit the motion imparted to saidarmature by energization of said electro-magnetic actuator.

8. Apparatus as claimed in claim 1 in which said switch comprises a pairof contacts and said means responsive to the speed of actuation of saidadjustable member comprises a pair of two-armed levers, each carryingone of said contacts, said levers being fulcrumed about a common axisand a spring connecting said levers so as to urge same into a relativecontact-opening position, one of said levers being connected to saidadjustable member so that a motion thereof causing said element toincrease the quantity of fuel tends to close said contacts contrary tothe tendency of said spring, when the mass resistance of the other oneof said levers exceeds a certain limit.

9. Apparatus as claimed in claim 1 in which said means ing, said massbeing movable contrary to the tendency of said spring when the speed ofactuation of said adjustable member in a direction increasing saidquantity exceeds a certain limit, said switch being mounted on 1 said:pump;

said housing for actuatioii'by saidmassupon movement thereof wmraryw agspring,"

10. Apparatus us Tim iagram 9 further comprising' means forretardingthe'restoration of said mass relative to said: housing by said"spring" during movement of said: adjustable member in a directiondecreasing said quantity. t t

11. Apparatus as claimed in claim 1 in which said electromagneticactuator is mounted on the housing of No' references cited.

